Physicians make use of catheters today in medical procedures to gain access into interior regions of the body to ablate targeted tissue areas. It is important for the physician to be able to precisely locate the catheter and control its emission of energy within the body during tissue ablation procedures.
For example, in electrophysiological therapy, ablation is used to treat cardiac rhythm disturbances. During these procedures, a physician steers a catheter with a distally mounted ablating element through a main vein or artery into the interior region of the heart. The physician locates the ablating element adjacent the cardiac tissue to be treated, and directs energy from the ablating element into the tissue to form a lesion thereon. Typically, the determination of a target site and the ablation of the target site are performed by a single catheter, which consists of an ablation eye electrode mounted at the tip of the catheter, and a mapping ring electrode mounted distal to the ablation electrode. This and similar catheter tip designs are described in U.S. Pat. No. 6,134,463.
It has been found that current catheter tip designs do not always provide a physician with enough resolution to accurately identify ablation site, causing the physician to perform multiple ablations in several areas. In particular, current catheter tips may detect far field electrical activity, which can negatively affect the detection of local electrical activity. This results in extended operation time and, often times, unnecessary tissue ablation. Furthermore, current catheter tips may include a temperature sensor located behind (or proximal) to the eye electrode for measuring the temperature of the tissue being ablated. Because the eye electrode is in between the temperature sensor and the tissue, and/or because the temperature sensor is not directly placed against the tissue, the temperature measurement obtained by the sensor may not be accurate.
As such, there is a need for a catheter tip that is capable of precisely measuring electrical signals from a heart in order to accurately determine an ablation site. Such catheter tip should also be able to accurately ablate a target tissue at the ablation site, and allow a sensor (in one is used) to accurately measure a characteristic of the tissue being ablated.